1: 1.) oxalyl chloride, DMSO, 2.) N-methylmorpholine / 1.) CH2Cl2, -50 deg C, 2 min, 2.) CH2Cl2, -55 to 50 deg C, 20 min 2: 1.) tin(II) triflate, N-ethylpiperidine / 1.) CH2Cl2, -45 deg C, 3 h, 2.) CH2Cl2, -80 deg C, 20 min 3: 82 percent / NaBH4, H2O / tetrahydrofuran / 1.5 h 4: 94 percent / imidazole, DMAP / CH2Cl2 / 3 h / Ambient temperature 5: 93 percent / H2 / 5percent Pd/C / ethyl acetate / 15 h / Ambient temperature 6: N-methylmorpholine N-oxide / (Ph3P)3RuCl2 / acetone / 72 h / Ambient temperature 7: BuLi / diethyl ether / 1.) -30 deg C, 30 min, 2.) -50 to 0 deg C, 1 h 8: BF3*Et2O / 2 h / Ambient temperature 9: t-BuOK, 18-crown-6 / pentane / 2.5 h / Ambient temperature 10: BuLi / diethyl ether / 1.) -80 to -30 deg C, 1.5 h, 2.) -60 deg C to r.t., 5 h 11: H2SO4, H2O / tetrahydrofuran / 0.42 h / Ambient temperature 12: HF, I2, H2O / acetonitrile / 48 h / Ambient temperature 13: 82 percent / 2,6-lutidine / CH2Cl2 14: 14 percent / CeCl3*7H2O, NaBH4 / methanol / 1.67 h / -60 - 0 °C 15: DMAP, pyridine / CH2Cl2 / 12 h / Ambient temperature 16: pyridine*HF / tetrahydrofuran / 1 h / Ambient temperature 17: Dess-Martin periodinane / 0.67 h / Ambient temperature 18: tetrahydrofuran / 1 h / -80 - -47 °C 19: Dess-Martin periodinane / CH2Cl2 / 0.42 h / Ambient temperature 20: pyridine, CSA / CH2Cl2 / 1 h / Ambient temperature 21: 88 percent / K2CO3 / methanol / 60 h / Ambient temperature 22: 90 percent / 2,6-lutidine / CH2Cl2 23: 1.) dicyclohexylmagnesium bromide / 1.) THF, -65 to -50 deg C, 35 min, 2.) THF, -65 to -50 deg C, 40 min 24: 93 percent / TBAF / tetrahydrofuran / 34 h / Ambient temperature 25: 3 Angstroem molecular sieves, TFA / CH2Cl2 / 0.6 h / Ambient temperature View Scheme

1.1: 98 percent / 4-dimethylaminopyridine; triethylamine / CH2Cl2 / 18 h / 20 °C 2.1: 95 percent / dimethylsulfoxide / 5 h / 85 °C 3.1: 84 percent / DIBAL-H / CH2Cl2; toluene / 4 h / -78 °C 4.1: 100 percent / NaBH4 / methanol / 0.75 h / 0 - 20 °C 5.1: 77 percent / triphenylphosphine; diethyl azodicarboxylate / tetrahydrofuran / 1 h / 0 - 20 °C 6.1: 95 percent / Mo7O24(NH4)6*4H2O; H2O2 / ethanol; H2O / 18 h / 20 °C 7.1: potassium hexamethyldisilazide / tetrahydrofuran; toluene / 0.5 h 7.2: 85 percent / tetrahydrofuran; toluene / -78 - 20 °C 8.1: 97 percent / 2,3-dichloro-5,6-dicyano-1,4-benzoquinone / H2O; CH2Cl2 / 2 h / 0 °C 9.1: DMSO; oxalyl chloride; Et3N / CH2Cl2 / 0.92 h / -78 °C 10.1: dibutylboron triflate; diisopropylethylamine / CH2Cl2 / 0.5 h / -78 °C 10.2: CH2Cl2 / 3 h / -78 - 20 °C 11.1: 12 mg / pyridine; chromium trioxide / CH2Cl2 / 0.33 h / 20 °C 12.1: 85 percent / HF / H2O; acetonitrile / 3 h / 20 °C 13.1: LiOH / H2O; 1,2-dimethoxy-ethane / 7 h / 80 °C View Scheme